Tenon anchor



R. J. HAUG 2,318,776

TENON ANCHOR Filed Aug. 4, 1940 'i i llllliii' i i t I: mm 2 BY M? lMgiNTOR. %2/2;7

ATTORNEY.

Patented May 11, 1943 UNETED STAT-ES FAT'ENT OFFICE TENON ANCHOR Richard J. Hang, Oakland, Maine ,4 Application August 4, 1940, Serial No. 351,311

6 Claims.

This invention is an improvement on tenon anchors such as'are used to hold tenons in mortises. It is particularly intended for holding-the round ends of chair legs in chair bottoms and for holding the round ends of chair braces in the legs.

Such a device should hold the tenon firmly and be held itself firmly in the mortise even when the parts have shrunk or have swollen. I

The device is particularly useful in locking a round tenon in a round mortise hole and it can be made and should be made of thin, tough metal with teeth so made that they will be caused to dig directly into the tenon, making its own hole and avoiding any longitudinal scraping action which might make a groove through which groove they couldslide out or become loose. I I

The device is also so made that when it is placed on the end of a tenon or at the opening of a mortise hole and the tenon is driven in, the

teeth will bite into the sides of the tenon and as the driving continues, the stock between the end of the tenon and the bottom of the mortise will be pressed out in such a way that it will be forced into the wood at the bottom of the mortise and particularly at four corners, the stock being rolled up so as to form a closed S-shaped'fold with two thicknesses in the material at the bot tom of the mortise hole and the rest of themetal between the tenon and the mortise conforming to their shape and with the teeth biting into the tenon.

In the drawing, Figs. 1, 2, 3, and 4 show the tenon anchor in place between a cylindrical tenon and a cylindrical mortise hole in the different stages from the time the anchor is placed until it is finally in place in the mortise hole. The tenon is shown in elevation and the member in which the mortise hole is made is shown in section.

Fig. 5 is an enlarged isometric view of my preferred form of anchor with a part broken away.

Fig. 6 is an enlarged elevation of the anchor shown in Figs. 1 to 5, as from the right with part broken away.

Figs. '7, 8, 9 and 10 are views similar to Figs. 1, 2, 3 and 4 of a modified construction of the anchor used with a tenon with a truncated conical end and a truncated conical mortise hole.

Fig. 11 is a diagrammatic plan view of a cylindrical mortise hole with an anchor in it, shown as broken away and in dotted lines the relative position of the S bend after the anchor is finally in position.

Fig. 12 is an elevation similar to Fig. 6 of another modified construction of an anchor.

In the drawing T represents a tenon which is shown as being cylindrical at the end and adapted to fit into a mortise M in a member N As shown, the member N andthe tenon T are of wood but they may be of other material.

My tenon anchor is made of a single piece A of thin, tough, fiat metal bent'in the middle at 6 to form arms B, B, which extend outwardly at any desired angle. Thefangle shown is about ninety degrees r g These arms B, B; are bent inwardly at '5 and then outwardly at 4 to'form an open Sb'end and thence extend straight or substantially straight atl0, It, as hands. 'Each of these hands ll], ID, has at its outer end an inwardly bent pointed tooth I and each side has a pair of inwardly or downwardly raking pointed teeth 2 and 3.

Each of these teeth preferably has a greater slope on its outer edge than at its inner edge so that when entering the tenon 'i't will tend to move inward and preferably the teeth on each side slope in opposite directions. 'This' construction avoids any danger of the'teeth forming two parallel grooves in which theyslide'and through which they can slide so as to be released.

Preferably the space between the S bends is less than the diameter l I of the mortise M or the tenon T so that as shown in Fig. lwhetherthe bottom bendS rests on the bottom of the hole or not, the part of each hand between the S-bend 4 andj the inside tooth 3 will rest-on'th'e edge l2 of the hole M and will be engaged by theedge [3 of the tenon as it is pushed in.

It will be seen therefore, as shown in Fig. 2 that as each tenon is pushed in, it bends up each hand l0 and as shown in Fig. 3, the teeth one after the other or all together penetrate the tenon which at the same time is being moved more and more into the hole so that as shown in Fig. 4 and Figs. 9 and 10, the open 8 bend is made a closed 8 bend, the ends of which at 9, 9, 9, 9, are forced into the wood at 8, 8, 8, 8.

The twofolds of this closed 8 band resist any pulling strain and in fact it is almost impossible to get the anchor out of its position and remove the tenon.

In Figs. 1 to 6, the arms B, B, are relatively short and the outside bend 4 is at about a fortyfive degree (45) angle. The other parts are so proportioned that as' the tenon T is pushed into the cylindrical mortise hole M, it forces the S bend at bends 4 and 5 to collapse and to spread out horizontally so that their end edges 9, 9 enter the wood as shown in Fig. 11.

In Figs. '7, 8, 9 and 10, the anchor C with arms F, F, has inside bends 25, 25 and the outside bends 24, 24 at more acute angles than in Figs. 1 to 6 while the arms are longer. 20, 20 represent the hands with the ends 2|, 2i and the tenon U is shown as going into a hole 29 which is somewhat tapered in a member V.

The result of this construction is that instead of the S bends as at and 4 tending to flatten out horizontally, the bends 25 and 24 tend to push up vertically so that in some respects this construction is stronger than the other,

As shown in Fig. 12, the anchor G may have arms such as H with bends at 35 and 36, the end edges of the inside bends 35 being extended out on each side as raking points 31 and 38.

The result of this is that whether these bends are made like 5 and 4 or like 25 and 24, these points 31 and 38 help to penetrate the wood and as their top surfaces are flat, it is difllcult to withdraw them after they have been forced into the wood.

I claim:

1. A tenon anchor, constructed of a single piece of thin, fiat metal bent in the middle to form arms which extend straight to an inward bend formed at an angular extension on each side and then to an outward bend to form an open 8 bend and which thence extend straight as hands, each having at its outer end an inwardly bent pointed tooth and at each side inwardly raking bent pointed teeth which on each side slope in opposite directions, the width of the anchor at the S bends being less than the diameter of the cylindrical tenon and mortise hole with which it is to be used.

2. A tenon anchor, constructed of a single piece of thin, flat metal bent in the middle to form arms which extend straight to an inward bend formed at an angular extension on each side and then to an outward bend to form an open 3 bend and which thence extend straight as hands, each having at its outer end an inwardly bent pointed tooth and at each side inwardly raking bent pointed teeth, the width of the anchor at the S bends being less than the diameter of the cylindrical tenon and mortise hole with which it is to be used.

3. A tenon anchor, constructed of a single piece of thin metal bent in the middle to form arms which extend with substantially straight, parallel edges to an inward and then to an outward bend, to form an open 8 bend and which thence extend straight as hands, each having an inwardly pointed tooth.

41 A tenon anchor constructed of a single piece of thin metal bent between its ends and havin two end portions adapted to straddle the tenon and an angularly deformable portion between and connecting said end portions and located forwardly of the end of the tenon, teeth on said end portions, said teeth being forced into said tenon as the tenon is forced into the mortise hole and said angular deformable portion being deformed so that three thicknesses of metal penetrate and interlock the wall of the mortise hole when the tenon reaches the ultimate position in the hole.

.5. For use with a wooden member having a round mortise hole and another wooden member formed with a tenon to fit the mortise hole; a tenon anchor, constructed of a single piece of thin, fiat metal of such a width that four chords of its width could form a square which could slip easily into the hole, the metal being bent in the middle to form arms which extend with substantially straight, parallel edges and unben-t to an inward bend and then to an outward bend, to form an open 8 bend and which then extend straight and flat as hands, each having an inwardly bent pointed tooth projecting therefrom, whereby when the tenon is driven home in the mortise hole the edges of the S bends are folded up in three thicknesses which penetrate the wood at four parts of the mortise hole and the hands are folded around the tenon with the teeth penetrating the tenon in a radial direction.

6. The combination with a member having a substantially cylindrical mortise hole; with a tenon having a substantially cylindrical end which fits the mortise hole and terminates in a flat end face; and a tenon anchor constructed of'a single piece of thin metal bent in the middle and lying flat between the end face of the tenon and the bottom of the mortise hole and formed with two parallel collapsed S-bends which extend in four places into the material of the member outside of the bottom of the mortise hole, the material of the anchor thence extending as arms along and between the mortise hole and the tenon and having inwardly extending teeth which penetrate the tenon, the width of the anchor at the S-bends being less than the diameter of the tenon and of the mortise hole.

RICHARD J. HAUG. 

